An electronic apparatus typically houses in a box-type housing various electronic components for realizing function depending on the electronic apparatus. As one of such electronic apparatus, there exists an electronic apparatus which holds a display plate having a display screen in the housing with the display screen appearing on an outer surface. Various electronic apparatus of this kind exist, such as, for example, notebook-type personal computers (hereinafter referred to as “notebook PCs”), cellular phones and game machines. In the following, description will be given using a notebook PC as an example.
A notebook PC is a personal computer basically having: a main unit which contains an arithmetic circuit including a CPU and the like, a storage device such as a hard disk drive, and many other electronic components, and which has a keyboard on the upper surface; and a display unit which has electronic components such as a display plate having a display screen and an antenna for wireless communication, and which holds the display plate with the display screen thereof appearing on an outer surface, and having a structure of the display unit being hinged to the main unit so as to be openable and closable.
Of this notebook PC as well as other portable electronic apparatus, there is a need for reducing the weight and thickness while securing a large size screen. As a measure for this reduction in the weight and thickness, it is practiced to use a metal plate such as a magnesium plate, for example, for the surface covering the back surface of the display plate of the display unit housing, and integrally mold the metal plate and a frame made of resin surrounding the periphery of the metal plate. One of the reasons for using a metal plate for the surface covering the back surface of the display plate of the display unit housing is to make the metal plate have the effect of an electrical shield so as to display on the display screen a clear screen free from noise. Japanese Laid-open Patent Publication No. 2000-148028 depicts an example in which a shield case is provided on the back surface of the display plate, and Japanese Laid-open Patent Publication No. 2006-330127 depicts an example in which a rear cover made of metal covering the back surface of the display plate and a joint section made of resin therearound are integrally molded.
Another reason for using a metal plate for the surface covering the back surface of the display plate of the display unit housing is reduction in the weight and thickness. To secure the shielding property alone, it is conceivable to use one made of resin instead of adopting a metal plate and secure the shielding properties by plating it with metal. However, securing a predetermined strength by one made of resin requires considerable thickness and consequently conflicts with the need for reduction in the weight and thickness. When a metal plate is used, a predetermined strength can be secured even by a considerably thin metal plate, which contributes to the reduction in the weight. However, if the covering is made by the metal plate alone, its shielding property in turn becomes a hindrance and an antenna cannot be contained in the housing. Therefore, the portion of the back surface of the display plate is covered with a metal plate and a resin frame is integrally molded around the metal plate, and the antenna is contained in the portion of the resin frame.
In order to form the panel forming the back side of the display unit housing by integrally molding a metal plate and a resin frame as described above is preferable from the viewpoint of securing the shielding property of the back surface of the display plate, securing good performance of the antenna, and reducing the weight and thickness; meanwhile, since the resin and metal plate being exposed would degrade the quality of the design, coating is applied to the surface. However, since there exist resin and metal, which are of different nature, in the surface, when coating is applied to the surface, it is difficult to be able to apply coating both to the resin and metal beautifully and maintain the surface in a beautiful state for a long period of time.
Although a beautiful state can be maintained for some length of time period by adopting an expensive coating material and giving two coats of a first coat and a second coat, for example, this is not always sufficient; for example, the coating material peels off if it is repeatedly touched by hands wet with sweat.
While Japanese Laid-open Patent Publications No. 2000-148028 and No. 2006-330127 disclose providing a shield plate on the back surface of the display plate or performing integral molding, they do not disclose any measures to address the problem described above.